A Study of Geological Structure in the Wanrung area , Central Range , Taiwan

• Main Authors: Gong-Ruei He, 何恭睿
• Other Authors: Ching-Weei Lin
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/78561014380768361208

碩士 === 國立成功大學 === 地球科學系碩博士班 === 96 === In the geologic zone in Taiwan we may divide the eastern of central range into Tailuko belt and Yuli belt. The earlier research indicated that the two metamorphic belts were divided by the northeastern-southwestern extended Shoufeng fault which was the division between the eastern high-pressure and low-temperature Yuli belt and the western high-temperature and low-pressure Tailuko belt. However, the precise location, character and details of this fault in visible reference are remained confirmative yet. Hence I picked the metamorphic rock area of Wanrung area to do this research by identifying and analyzing from image and field work. I collected samples alone the course for analyzing the illite crytallinity and the paragonite exist index. I also estimated the relatively dynamic characteristic of Shoufeng fault by observing the shear plane and shear direction of microscopic structure. The results indicated that (1)The rock types of the outcrop in Tailuko belt was quartz-mica schist, marble, chlorite schist and serpentinite and the Yuli belt was composed by metamorphic sandstone, chlorite schist and graphite schist.We can tell the obvious difference between the two different metamorphic belts.(2)A 2km in width of mylonite zone was found in the boundary of the two different metamorphic belts. This founding represents the evidence of the fault dislocation between the two different metamorphic belts.(3)According to the analysis of the illite crytallinity, there was a region that had the low crystallinity index and the obviously better crystallinity. This region could be a good contrast with the mylonite zone.(4)According to the analysis of the paragonite exist index found out that in the Yuli belt and the mylonite zone are 7 samples indicated the region of high-pressure mineral─paragonite and it was not found in Tailuko belt.(5)According to the results of microscopic structural analysis found out that the mylonite zone of the shear structure in this research region had the same direction. The other near regions had the obviously shuffling directions that indicated the mylonite zone had the same shear direction therefore the dynamic pattern of the mylonite fault zone had the characteristics of left-handed and thrust-slip fault.